My Acctim in the w/shop had changed by 08:30 ( GMT ).
No idea where it derives it's signal.
When I replace the battery it gallops around to 12 o'clock then usually waits a bit then resets to correct time.
Had it for years, always seems to perform. Don't recollect ever having to intervene.
D.
Just found the Instructions PDF. Apparently MSF, 60 KHz, Anthorn, Cumbria.
Edited By Dave Daniels on 01/11/2021 09:26:42
Edited By Dave Daniels on 01/11/2021 09:27:00
Edited By Dave Daniels on 01/11/2021 09:36:16